Abstract:
Quantum correlations between particles are usually formulated by assuming
the persistence of an entangled state after the particles have separated. When
entanglement is present, Bell‘s Inequalities are violated but when entanglement
is destroyed, Bell‘s inequalities are satisfied.
The aim of this work is to build computer program using Matlab software to
simulate Ekert protocol of quantum cryptography by implement event-based
simulation method. And by used two types of probabilistic polarizing beam
splitter. Since we used the argument of Malus intensity law to represent the
quantum probability amplitude for each single photon in type1 and the
Hadamard transformation of single photon to represent quantum probability
amplitude for each single photon in type2. The program calculated the
quantum correlation of each two polarized entangled photons as a value of Bell
inequality (S) . The obtained results of (S) value after implemented suitable
time tag model was in average S = 2.6 for type1, and S = 2.7 for type2. And
this results investigated strong quantum correlation, and very agreement with
that result of maximum correlation expected by quantum mechanics theory
calculated for polarized entangled photons (S =2.83).
After running the simulation program of Ekert protocol the results of
established secret key between two legitimate users and the variation of (S)
value showed very good ability of program for detecting eavesdropper, that by
an obvious decrease in (S) value. When eavesdropper was present the value of
(S) decreased to S = -0.29 and S = 0.19for type1 and type2 respectively.
